In the typical disc memory, the recording medium used is a detachable disc module. Typically, an installation will have many mechanically identical modules which can be mounted in any drive designed to accept them. Because of the problem of dust and dirt contaminating the disc and causing the read/write head to rub the recording surface from the disc, the usual procedure is to protect the disc from dust and dirt when not in the drive by enclosing it in a housing. As one might expect, a large number of different approaches have been employed in designing such housings. One approach has been to design the housing so that it is totally removed from the disc when the disc is mounted in the drive. Another approach employs a housing which permanently encloses the disc, and has one or more access doors permanently attached to the housing, and which are opened at some stage of the mounting procedure to allow access to the disc. A third approach is a composite of these two, employing a permanent housing and a so-called "bottom cover" or dust shield which is detached just prior to mounting the module in the drive.